Audio advertisers spend great sums of money and countless hours to produce advertising campaigns aimed at maximizing the response from the listeners. By tailoring the advertising media, the timing of the audio play, the content of the advertisement, and many other variables, advertisers can influence who will or is likely to hear the advertising message. In this way, audio advertisers can concentrate their efforts on reaching the listeners who are most likely to respond to their advertising message. Generally, advertisers are willing to pay more money for advertising slots that allow them to deliver their message to the most members of their target audience. Because advertisers have a limited budget and limited time to manage campaigns, they are eager to identify which campaigns are effective and, perhaps more importantly, which are not.
At the same time, broadcasters rely on advertising revenues from selling advertising air time to cover operational expenses. Thus, it is to the broadcaster's advantage to sell all available advertising air time in order to maximize income. Unfortunately, a significant portion of the available advertising air time is not sold due market demand factors, poor ratings, station inefficiencies, trafficking logistics, programming logistics, and other factors. In fact, radio stations, for example, often operate with daily unsold advertising inventory that accounts, on average, for up to 30% of the total advertising air time. This unpaid air time has traditionally been filled with public service advertisements, bonus advertisements, remnant advertisements and/or low-priority advertisements.